/**
 * This file is part of 1genia trampoline
 * Copyright (C) 2007 1genia (contact@1genia.com)
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; version 3 of the License. 
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details. 
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; see the file COPYING.TXT.  If not,
 * write to the Free Software Foundation, Inc., 51 Franklin Street,
 * Fifth Floor, Boston, MA 02110-1301, USA. 
 **/
package com.genia.toolbox.web.gwt.form.client.widget.item.impl;

import java.util.HashSet;
import java.util.Set;

import com.genia.toolbox.web.gwt.form.client.widget.item.ItemWidget;
import com.genia.toolbox.web.gwt.form.client.widget.item.ItemWidgetModifyListener;
import com.google.gwt.user.client.Timer;

/**
 * the implementation of <code>ItemWidgetModifyListener</code> that checks that
 * the value of the item is acceptable.
 */
public class ValidateModifyListener
    implements ItemWidgetModifyListener
{

  /**
   * list of <code>SimpleItemWidget</code> to check in the next run.
   */
  private static final Set<ItemWidget> TO_VALIDATE = new HashSet<ItemWidget>();

  static {
    /*
     * the Thread the will do each validation every 1000 ms.
     */
    new Timer()
    {
      @Override
      public void run()
      {
        synchronized (TO_VALIDATE) {
          if (!TO_VALIDATE.isEmpty()) {
            for (final ItemWidget itemWidget : TO_VALIDATE) {
              itemWidget.validate(new DisplayErrorValidatorCallback(itemWidget));
            }
          }
          TO_VALIDATE.clear();
          schedule(1000);
        }
      }
    }.schedule(1000);
  }



  /**
   * the method that is call when the value of the item change.
   * 
   * @param itemWidget
   *          the item that changed
   */
  public void onModify(final ItemWidget itemWidget)
  {
    synchronized (TO_VALIDATE) {
      TO_VALIDATE.add(itemWidget);
    }
  }

}
